David M. O’Malley, MD, Department of Obstetrics and Gynecology at The Ohio State University College of Medicine and the director of the Division of Gynecologic Oncology at the OSUCCC "“ James speaks about ESMO 2021 Abstract – 724MO – Balstilimab (anti-PD-1) in combination with zalifrelimab (anti-CTLA-4): Final results from a phase II study in patients (pts) with recurrent/metastatic (R/M) cervical cancer (CC).
Background:
The treatment of R/M CC in the second line remains a serious clinical issue. Multiple cancers have been successfully treated by blocking both the PD-1 and CTLA-4 immune checkpoints. We present the results of a large single-arm Phase II trial in patients with R/M CC to assess the safety and antitumor efficacy of the anti-PD-1 antibody balstilimab (bal) in combination with the anti-CTLA-4 antibody zalifrelimab (zal).
Methods:
For up to two years, pts were given bal 3 mg/kg Q2W in conjunction with zal 1 mg/kg Q6W. The primary outcome was the objective response rate (ORR) as determined by independent evaluation according to RECIST 1.1; secondary objectives were safety, DOR, and survival.
Results:
A total of 155 people were given bal plus zal (safety population). The efficacy-evaluable group consisted of 125 patients with detectable illness at baseline and one prior line of platinum-based treatment in the R/M setting, with results shown in the table below. The average study duration was 19.4 months. The combination was found to be tolerable, and no additional safety signs were discovered. Grade 3 associated AEs were detected in 33 patients (21.3%), with ALT rise (3.2%), anemia (1.9%), and diarrhea (1.9%) being the most common. In 15 points, treatment was stopped owing to a connected AE (9.7 percent ). Immune-related AEs were reported by 69 patients (44.5%) (12.6 percent grade 3); hypothyroidism (13.5%), hyperthyroidism (13.5%), and diarrhea (each 7.1 percent) were the most prevalent all-grade occurrences.
Conclusions:
In patients with previously treated R/M CC, the combination of bal and zal showed excellent response rates (including full remissions), DOR, and OS. Patients with PD-L1+ tumors saw the most clinical benefit, however activity was also found in the PD-L1- group. The therapy plan was well-received.
Clinical trial identification
NCT03495882